Designed especially for Prowin and SHS Hop-up units to address the issue of axial displacement of the chamber caused by two factors.

Firstly, the outer barrel and the chamber not fitting snugly - this is due to the difference in tolerances between various gun brands. The two fins on each side of the chamber may not provide adequate hold to prevent lateral movement of the hop up chamber. The True Centering Unit (TCU) will bridge this gap to prevent unwanted movements.

Secondly, loose magazines can twist the hop-up and inner barrel away from the center. This is further caused upon firing when the BBs move up the chamber for loading. The vibration can cause the hop to sway from side to side causing inconsistencies in your shots.

In general, securing anything that moves in the rifle, around the hop-up and inner barrelcan improve shot consistency.

Once the TCU is fitted, the Prowin chamber will be tightly fitted in place and sitting on the true center position to prevent BBs from swerving to the left or right.

Features

• Prevents tilting of the hop-up unit
• Locks snugly into the outer barrel and forces the hop up chamber and inner barrel perfectly on the horizontal axis
• Prevents magazines from shifting the hop up chamber
• True centering to prevent your BBs from swerving away from the target.
• Tough Polycarbonate Construction

Compatibility

• Prowin Chamber
• SHS Chamber

Installation Notes
Different brands and models of the M4 have different tolerances. It is recommended to remove the outer barrel and test the TCU with the hop-up chamber. In some cases, you may need to lightly sand the end side of the TCU slowly and incrementally until you achieve a snug fit into the outer barrel slot."